I worked at an apt complex, and they had 12 condensers on one end of the bldg. Every one of them were labeled wrong, tstat wires to wrong units and whips were all wrong as well. Took about 3 hours to correct it all. While I was working on it some of the residents came out to "watch the show" from my cussing the installers, they were wondering why they had $300+ electric bills and some had $50 bills. I let the manager explain it to them. It was also only about six month old property, I told her this should all be under warranty but it was Friday evening and you know how that goes. I'm really enjoying the videos!
Oh jeez. I was working on a roof that was all mislabeled. My boss at the time came and condemned the compressor. Told the lady she needed a new system. She waited a full week in the middle of a heat wave and she was 86. The day he was being the condenser for us to pull up onto the roof because he would do that if he didn’t absolutely need a crane. Make us carry it up four floors then pull it up thru the hatch. Well turns out it was the wrong condenser but he never told the woman and still changed it out. Needless to say I quite. I don’t like liars (it wasn’t just that lie it was so many other lies to customers) and I don’t think anyone should be carrying condensers up any flights of stairs. It wasn’t the first time I’ve carried at least 20 in the last four years working for him in Boston up 5 to 7 flights sometimes in the winter pulling them up the hatch. Guy was such a cheap prick. My new company is honest and does everything properly.
I’m employed as a mechanical designer. I’m pretty used to negative complaints. These videos are gold though since I listen better when complaints are constructive. It’s hard to foresee all of the issues that may occur, after the unit has 10+ years in service in an unknown temp/relative humidity, installed by unknown tech. Thanks a lot for making these videos.
Great Detective Work!! It is kind of funny thinking about these mislabeled t-stats and the trouble they caused. People complaining that the room is freezing while the servers go and adjust the units heat setting for another room where the guest are all complaining about how hot it is in that room. Could be a great comedy skit.
Great find: Miss-labeled stuff can drive you nuts. To bad some installers don't seem to care and just slap numbers on equipment. Thanks for that great video. P.S. I had a restaurant that had two three phase electric water heaters that would not keep up to the demand of the dishwasher. I found that they were on a 208 volt three phase system and the elements were 240 volts. The loss of voltage doubles the loss of wattage. Installed the 208 volt elements and not more issues.
Nice work unraveling that mess, and walking us through how the room got to that high of a temperature, great explanation and troubleshooting as always.
This video shows the importance of label everything and make sure your label are clear and correct. I have seen so many issues and outages caused by someone mislabeling something.
I will be going live on RUclips this evening 9/9/19 @ 5:PM (west coast time) to discuss my most recent uploads, answer questions from RUclips comments, the Live chat, and from emails if you can come check it out here is the link >>>> ruclips.net/video/6YDWpK7UEiU/видео.html
HVACR VIDEOS one question I do have. When you gave us a tour of your new van, I thought you had said you would give us an update when you got it all set up, have you got to that point yet? Or did I miss it?
You should get a meter with a Low impedance input function (Lo-Z). Fluke have good ones. That way you will be able to save time troubleshooting and confirm whether a wire has ghost voltage present just like the Cool (Y) cable did in your video, whether it be capacitive coupling voltage or voltage from a triac. A normal high impedance volt meter will always pick up ghost voltages, which is why i have a dual impedance meter for these type of scenarios as seen with the disconnected thermostat wiring.
how many times do you come across a bad triac i have once and it was on a old unit about 30 yrs old and all the wires are black and numbers are on but all info on the diagram is gone.
If you do a search on forward leakage current you will see some good articles on what happens with some electronic power switching devices .. one thing to remember is that these forward leaking voltages and current are additive - I had a truck stop fueling system that wouldn't shut down ... the state was about to shut the place down because the automatic leak detection system would not work unless the supply pump shut down for at least 15 min every 24 hours. Non of the pumps were calling for fuel but the relay that energized the supply pump was getting enough of a signal to pick up. Investigation showed the cumulative forward leaking voltage and current from all the pumps was enough to cause the supply pump system to stay on - I put ballast resistors from the output of the electronic power relay to the neutral to bleed the voltage and current off at every fueling station thereby causing the forward leaking voltage and current to be reduced to zero and allowing the supply pump to shut off when no dispenser was calling for fuel... it was quite the learning experience .. you have to be aware of this issue when dealing with electronic power switching devices. These issues also rear their heads when mixing electronic power switching and computer sensing circuits- you have to be carefull using low impedance systems to load electronic components - your testing can kill the components if you exceed their capabilities. Be Informed and be safe
I have mixed opinions on Dedicated Outdoor Air Systems (DOAS) for tempering outdoor air separate from the main space conditioning. It is required in some cases here in Washington, but it does add more components, ductwork, and system complexity that can confuse building owners and maintenance staff, leading to more issues down the road. Having a simple RTU, fan coil, split unit, etc. with a properly functioning economizer is still the simplest way to bring in normal amounts of outdoor air. DOAS has its place, and as a design engineer I have done them plenty of times, but they don't always make sense. Love the videos!
Hey Chris, you're awesome. Analytical thinking involves a methodical step-by-step approach to thinking, which allows us to break down such complicated technical problems into single parts. The way of visualizing your solutions make us understand them very quickly. Thank you for the great work. - Murat
Very interesting video, the rabbit holes were so plentiful. I could see how someone (probably me) could jump down a hole and spend so much time trying to figure out the problem. Thanks for offering a bird's eye view of the caution you take when drawing a conclusion and then not being sold on the conclusion being the answer until it's proven. As far as the mislabeling, I guess that's where I'd need to summons the patience and get the job done. As usual, you've brought another quality video. Thanks PS - The economizer bringing in make up air that ranged around 96 degrees was on point. The minimum make up setting contributed heavily to the heat load in the room and the consideration is easily overlooked in the delta T assessment.
YORK Air handlers are very reliable. My company has dealt with them for years, and I can say from first-hand experience that they are great. They offer unbeatable competitive pricing and have amazing quality with an awesome Customer support team, as well as, technical team.
Voltage a little low, lol. Just as I was going to say trans set up wrong voltage you caught it.! Very common issue brother. Guys, this could be a problem with long runs of thermostat or control wires between ac and stat or energy management system. Good job, brother. Good lesson on checking t stats. Pro 8000 Honeywell? Love those stats.
I first started watching your videos when I first got into the industry and they were definitely helpful but a lot of times it was over my head. Now that I have a more practical understanding your videos are teaching me so much. Thanks for the help and keep up the great work!
Awesome Video!! You are 100% right about outside air needed to be conditioned beforehand. The commercial building that I work in has a ton of air handling units but we have 6 big outside air handler units that pump the air to the outher air handles and the ducts are labeled outside air. They have chilled water coils and steam coils for heat and eveything is controlled by a BMS system.
The ever elusive Phantom voltage. I keep a resistor on my van that I put between the common and the suspect wire that simulates a load if my voltage drops like it did in your video I call it as a bad relay contact on the t-stat and replace the stat. What captured my mind in this video was that because of the low voltage between R and C because of the transformer is it possible the relay was "chattering" and experienced excessive wear. I know on unloading compressors they have an H bridge to get DC power to hold the valve shut with single phase. Again because it opens and closes rapidly or "chatters" but that's also way more force required to hold those valves shut. Thought provoking video thank you!
I watch the whole video I love it I've been through the same situation and that's a headache when you are alone. You kept your cool in that 108 degree weather ! I would have been a bit cranky LOL
Hey Chris, my bet is that thermostats were swapped by other technicians on previous service calls and the banquet room wasn't being used at the time so that's where the broken one was parked instead of the technician just taking the time to get a new tstat and base and doing the install. The labeling would be better placed on the wall, not on the tstats.
Watching these videos while attending school has been great since everything starts to make sense over the months, would love if you came to UEI in Riverside
I upgraded my thermostat to Honeywell, battery backup is so nice! I also like their programming for daily schedules, helps lower the utility bill without sacrificing comfort.
Here's why you saw 24V on Y1 and Y2 with the thermostat wires disconnected from the York board. The thermostat is very most likely using triacs instead of small relays to switch the 24V signals. A triac does not act as a switch or relay where it completely disconnects the output from the input. It only increases its resistance so as to prevent sufficient current from activating the load. I believe that a non energized triac has an impedence in the range of 40 Megaohms. We can read the input voltage of the triac at its output when disconnected from its load with good multimeter because the impedence of a multimeter capable of reading very resistance is very high and as such makes the impedence of the triac negligable (to some extent) in the circuit with the multimeter. The best way to test a triac is to connect it to a known good load (a 24VAC relay carried around) and see if it is triggered when the thermostat calls. In your case, you made a good call with the thermostat being that it was calling but not triggering the load. You can find triacs on thermostat and also many BAS programmable PLC's. They operate silently and can also be switched at a high rate for baseboard or duct heater pulsing. I work with Alerton controls daily and 98% of the current controllers use triacs for their digital outputs.
Dorian was like being in the Army...hurry up and wait. No wind, a little rain, maybe an inch for central and west Florida. However watching the news, one would think armageddon was upon us.
When you were explaining the voltage fluctuations during the summer I found thy very interesting. It almost makes me question the need for surge protection or low-voltage protection equipment.
brownouts are the legal term and way for companies to do that and when its hot everyone turns ac on so you get a heavy load and drops your voltage, as long as its not more then 10% your good most of the time and yes you need a surg protector in that case if they bolster the power and the units turn off you have a high inflow,
Good vid ! i Remember when i was first starting out the first thing i learned was allways Check your Transformer tap & secondary voltages. i used to find them on the wrong voltage All the time. Really common installer error in southern california i found. Ftngot - ALLWAYS The first thing u should do when u get to a package unit is check your transformer taps & voltage no Higher than 29 volts. at 30 volts Thermostats tend to Fry , thats what ive found anyway. i Like no higher than 27 volts & no lower than 23 volts. Good info on the Min outside air damper setpoint , if u have a unit struggling , You could Allways close that damper temporarily in the summer. Re: Ftngot - Easy way to tell if its a bad thermostat in this case is to shut off unit, go down to thermostat , remove wires & wire nut together wires on R, G, Y1 & Y2. Go back up to roof turn on unit & if everything works. whala, junk thermostat. By the way - I've Allways Loved that feature on Venstar thermostats or similar. Ftngot - i Allways Recommend You set up a Thermostat so, When Power From Roof unit is Dead Thermostat goes Blank. it's a Awesome Troubleshooting tool. i Will ALLWAYS Do it that Way. Batteries in Thermostats is crap, ALLWAYS WIRE IN THE COMMON WIRE. Makes Your Life a Whole lot easier ! Wayyy Less Thermostat Problems with a Common wire hooked up i have found.
Good call on changing over from 240 to 208 volts on the transformer. That was an issue I ran into a few years ago where there was 208 going into the units and they were plugged in for 240. More than half of the transformers fried on 14 newly installed package units
Though I very seldom have worked with that many stats clustered I can see your frustration and returning to correct it. Not OCD but just plain common sense!
Good tip on the 208/230 tap selection on the 24V transformer, I've seen most units never have an issue with it but change it over anyways especially since York tech support had informed me once that sometimes their boards can act up when they get on the lower end of control voltage.
@ 6:05 good idea to use meter for current draw through jumper or total current from transformer secondary. before just stuffing in a new t.stat, yeah I've cooked a few new ones myself, within hours to days =p
not to sound like a ass but that would be a super easy call for most commercial techs, you will get to the point that its second nature. people will say i have this unit or the color of the unit and you will here the problem and know what it is, and leaks that occur in the same place thanks to bad design am looking at you trane
It may be an easy call but everyone has a method and way they go about things. And I watch his videos and he goes at each issue with his same style and always gets to the point and I respect that. Any trade you learn you start off with no style then you develop it thru the yrs. also, simple shit stuns the most vets all the time
Wish we had someone like you in Phx haven't found one yet. I seem to end up with Techs that guess at solutions more than discovering what is wrong. I manage 5 units about 25 tons worth.
well if i move there you got me, i manage at my building 12 units 200 to 250 tons each and 8 16 ton units, and hundreds of vav boxes and i do all the programs for the crappy andover continuum system. have been in the trade for 22 yrs now did a lot of the gov buildings and cooling towers and a bunch of others, i hate dealing with "tech"s mechanics also known as parts changers, these younger guys just dont look half the time. they guess what it is on the way to the call
Lo-Z function on your DMM would / could have helped. I've run into many high impedance circuits that show unloaded supply voltage on a DMM. As soon as you apply a connected load, the voltage disappears. In the early days we used a wiggy tester (before Lo-Z was an option on DMM's), but if you don't have a DMM with the Lo-Z functions you can use any known good load appropriate for the voltage being tested.
Thanks, I will be going live on RUclips this evening 9/9/19 @ 5:PM (west coast time) to discuss my most recent uploads, answer questions from RUclips comments, the Live chat, and from emails if you can come check it out here is the link >>>> ruclips.net/video/6YDWpK7UEiU/видео.html
Just a heads up . Here on Long Island New York we have the same issues with transformers being tapped to 240. When in actuality it was 208 . Great info as usual
I sold industrial HVAC and my boss has sold a used direct-fired air makeup that had work for a year and when they tried to start it up the unit would not run. When I went to the roof and open a panel and tried to start the unit fired right up. The air was dumped into a square duct the four dampers on the discharge, well a the dampers were almost completely shut so the sensor said there was not enough air flow to start. So I talked to the maintenance guy and had him remove a damper the shot down a hallway, never had a service call on that unit again.
Just had a similar issue at a Goodwill store. A second company had come out and installed 5 new wireless Emerson thermostats and wireless sensors. Not only had they labeled everything incorrectly but half of the sensors didn't even have batteries. This lead to three t-stats not being able to send a signal out to the units. What a mess!
2:50 start up tech fail. Great video, do you carry alligator jumpers ever? Last friday I had 11 York's to run PM's on at an AMF bowling center in Rochester NY. The jumpers come In Handy testing rtu functions. Great vid!!!
Doing a great job . Looks like the Nat. gas code is not very strict in California no dirt pockets ect. In Canada it is very strict ,Everything must be to the latest code .
It’s crazy how many package units I come across that are 208-3 phase voltage and the transformer is tapped for 240 volts. I change them everytime I see it, because just like in your video, there is a big difference in the low voltage output without a load on the unit. It will go from something around 23-24 volts without a load to 26-28 volts which is what you want.
Very nice work! Hard to believe someone would go to all that trouble to lable the thermostats, and then do it wrong lol. Have heard there are CO2 sensors to control the economizer for fresh air. That way it only takes in outside air when it's necessary, not all of the time.
Yes we do use c02 sensors but we will still usually set the minimum outside air at a certain setpoint than the c02 sensor will adjust the damper open as more people occupy the building. I will discuss this on my stream tonight, I will be going live on RUclips this evening 9/9/19 @ 5:PM (west coast time) to discuss my most recent uploads, answer questions from RUclips comments, the Live chat, and from emails if you can come check it out here is the link >>>> ruclips.net/video/6YDWpK7UEiU/видео.html
Not really familiar with the economizer set up do to being in Florida, too humid for many applications but, have worked on some carrier and Trane over the years. Question is, don't the economizer use Enthalpy and temp to adjust the level of outside air allowed into the Return Air? And if yes, would the fresh air shut down in the case of 100 degree plus outdoor ambient or are they set up to allow a certain percent of fresh air regardless of Outdoor temp? I know that's a lot😄 Thank you!
coolezum You have several ways of controlling an economizer including outdoor temp, enthalpy and dual enthalpy. No matter the type of control you will have a minimum position, usually in the 10-20% range. So whenever the blower is running you are pulling in outside air to maintain fresh air requirements and building pressure. When the criteria is met for free cooling, your economizer will open to 100% upon a call for cooling and again, their is several methods to control that. Ie.say you have a temp setpoint of 55degrees for free cooling and it is below 55deg. Outside, instead of energizing the compressor it will open the economizer. Same situation with enthalpy. If outdoor air is below the enthalpy set point, it will utilize outdoor air for cooling instead of mechanical cooling. In dual enthalpy, the unit will monitor building and outdoor enthalpy and utilize whichever is suitable. You can also monitor return, outdoor and supply conditions and use a combination of economizer and mechanical cooling to maintain a specific supply temp. You can also have demanded ventilation utilizing IAQ requirements to call for economizer operation. As with anything in this trade, read the damn manual! I can’t say that enough. It’s a simple thing we all to often don’t do then can’t figure out why we have issues properly setting up new equipment or diagnosing equipment we encounter.
Kevin King thanks man, good explanation. I knew most of the details but, just was not sure if there was a way to shut down the economizer in an event such as happened on this problem, where as no cooling ,yet was dumping OSA into the building. No safety where as a sensor could close the economizer off completely in this situation. Cool man, peace
@@kevcooh9 and the econ is used as stage 1 cooling on some units like carrier then stage 2 is the compressor and thats with lower outdoor air temp and if the unit cant pull down it will say the hell with the econ and bring the 2nd compressor on so in lower temps in a club or bar a place that has a high heat load you will see the compressor and econ on then 2 comps and no econ.
208V vs 240V is generally 3-phase vs single phase service even with a single phase unit. This is bc 208V is phase to phase voltage and 120 phase to ground vs 240V split phase which is 240V line to line and 120V line to ground.
Typical three phase is delta wye, which provides the 208 and 120. Atypical is delta high leg or wild leg... gets you 240, 120, and 208 volts. Then there's delta only, no neutral, usually for industrial motors that isn't seen in this stuff.
thermostat not passing enough current, bad relays or connection. or corroded splices/connections somewhere along the thermostat wiring. fire system relay?
if I had a $1 for every unit I found the trans tapped on the wrong tap I would be rich. Also digital meters are great, but they put no load on the circuit and they will show transient voltage when there is really nothing there.Sometimes using a "wiggy" or an analog meter is better.Mismarked is worse than no markings sometimes
hahahaha a wiggy still have a old wiggy use it to show the newer guys what i started in school with and remember 10 wraps of t-stat wire to read the mili volts for the heat anticipator load
Makes you wonder if that unit is the right solution if it has to pull triple duty cooling the room, cooling the fresh air, and dehumidifying all of it. Perhaps there is a more efficient alternative?
208Y/120V 3phase is fairly common all over the place for light commercial, strip malls, until you get into larger industrial complex which are 480Y/277V as primary voltages. around here they often have their own large pad transformer/s with 14.4KV or higher, being stepped down to 208Y/120 or 480Y/277V and another step-down inside for lighting and other smaller loads. it really depends on the area and existing grid, it can vary from section of town to section of town depending on age of the grid and upgrades. I wont delve into "delta" supply voltages. anyway often you'll see single phase 480Y primary to 240/120v transformers just for common use outlets and devices.
Yeah I've come across some funky delta supplies....... the most memorable was a corner grounded delta....... the first time I came across that I was on the phone with an electrician buddy right away.....
Yeah- any time you see a breaker box with every third breaker missing BEWARE - that missing breaker will be the wild leg... I have seen some electricians be very embarrassed by grounded deltas.
Is that a Simpson 260 analog multimeter on the corner shelf behind you? If so, did you ever use it, or is just a piece in your collection? Another good video, by the way.
One of the worst mislabeled items would be the fire suppression system in the restaurant. We would take the charge bottle out of the Ansul cabinet and then cut the cable at the fry station. What a mess it made, there was powder, err sorry Ansul, chemical all over the kitchen.
240V/208V is depending on the supply, if the transformer is a 2ph 180° 120V the voltage between the two phases is 240V; if its a 3ph 120° 120V you messure 208V between two phases; as the us is mostly 2ph 180° for residential areas its more common to find 240V in some areas
They shut down plants left and right because of "environmental" reasons. Then they purchase power from out of state. Guess what, the other states use more power in summer because it's hot as hell. There's increased loads from 60 million people at once, something has to give. Voltage sags. Not a big deal, most the time, most equipment are built to handle the variance. Sags too hard and we'll, you get Brown outs that does affect equipment. Then you get power stations tripping and blackouts. California wants their cake and to eat it too. Simply doesn't work that way. We pay peak pricing out here in the west because when there is peak usage, the utility usually has generators on standby they can fire up, basically a makeup unit. I think gas burning. Either way it costs a lot more to get that going but that's what usually provides the power boost during the heaviest of loads. California... well, if it's cloudy or not windy all those "green sources" don't output shit and you get California power problems. A couple nuke plants would fix all that but most the idiot voters won't do a thing. Inland empire is newer build and lesser money than the big cities with their rich folk so they'll always be the red headed step child and take the brunt of issues.
@@etherealrose2139 California has 3 main power companies: PG&E for Northern and Central CA; SoCal Edison for most of southern part of the state: and SDG&E for San Diego area. SoCal also gets power in summer from West Coast Intertie from Grand Coulee Dam in WA. In winter excess power is sent north for electric heat in WA and OR. At least that's the way it used to work.
I worked at an apt complex, and they had 12 condensers on one end of the bldg. Every one of them were labeled wrong, tstat wires to wrong units and whips were all wrong as well. Took about 3 hours to correct it all. While I was working on it some of the residents came out to "watch the show" from my cussing the installers, they were wondering why they had $300+ electric bills and some had $50 bills. I let the manager explain it to them. It was also only about six month old property, I told her this should all be under warranty but it was Friday evening and you know how that goes. I'm really enjoying the videos!
LMMFAO....Been There Done That...Our Installers Did It On Purpose, And Did Not Show Up The Next Day...Residents Were Not Happy With Me In And Out
Oh jeez. I was working on a roof that was all mislabeled. My boss at the time came and condemned the compressor. Told the lady she needed a new system. She waited a full week in the middle of a heat wave and she was 86. The day he was being the condenser for us to pull up onto the roof because he would do that if he didn’t absolutely need a crane. Make us carry it up four floors then pull it up thru the hatch. Well turns out it was the wrong condenser but he never told the woman and still changed it out. Needless to say I quite. I don’t like liars (it wasn’t just that lie it was so many other lies to customers) and I don’t think anyone should be carrying condensers up any flights of stairs. It wasn’t the first time I’ve carried at least 20 in the last four years working for him in Boston up 5 to 7 flights sometimes in the winter pulling them up the hatch. Guy was such a cheap prick. My new company is honest and does everything properly.
I’m employed as a mechanical designer. I’m pretty used to negative complaints. These videos are gold though since I listen better when complaints are constructive. It’s hard to foresee all of the issues that may occur, after the unit has 10+ years in service in an unknown temp/relative humidity, installed by unknown tech. Thanks a lot for making these videos.
Great Detective Work!! It is kind of funny thinking about these mislabeled t-stats and the trouble they caused. People complaining that the room is freezing while the servers go and adjust the units heat setting for another room where the guest are all complaining about how hot it is in that room. Could be a great comedy skit.
Great find: Miss-labeled stuff can drive you nuts. To bad some installers don't seem to care and just slap numbers on equipment. Thanks for that great video. P.S. I had a restaurant that had two three phase electric water heaters that would not keep up to the demand of the dishwasher. I found that they were on a 208 volt three phase system and the elements were 240 volts. The loss of voltage doubles the loss of wattage. Installed the 208 volt elements and not more issues.
After a long day of studying and having lecture I spend every free minute watching your videos
Nice work unraveling that mess, and walking us through how the room got to that high of a temperature, great explanation and troubleshooting as always.
This video shows the importance of label everything and make sure your label are clear and correct. I have seen so many issues and outages caused by someone mislabeling something.
Whoever put the alarm stuff inside those units is a genius! I need to do that!
I love how you explain what your thought process is going through as you troubleshoot! You make this work look easy 😉.
Experience does that. it is NOT By any means.
OcRefrigeration , Hvac & Electrical Video's. Oh I understand that!
I will be going live on RUclips this evening 9/9/19 @ 5:PM (west coast time) to discuss my most recent uploads, answer questions from RUclips comments, the Live chat, and from emails if you can come check it out here is the link >>>> ruclips.net/video/6YDWpK7UEiU/видео.html
HVACR VIDEOS one question I do have. When you gave us a tour of your new van, I thought you had said you would give us an update when you got it all set up, have you got to that point yet? Or did I miss it?
Great diagnosis skills. Working on improving mine.
You should get a meter with a Low impedance input function (Lo-Z). Fluke have good ones. That way you will be able to save time troubleshooting and confirm whether a wire has ghost voltage present just like the Cool (Y) cable did in your video, whether it be capacitive coupling voltage or voltage from a triac. A normal high impedance volt meter will always pick up ghost voltages, which is why i have a dual impedance meter for these type of scenarios as seen with the disconnected thermostat wiring.
This!
how many times do you come across a bad triac i have once and it was on a old unit about 30 yrs old and all the wires are black and numbers are on but all info on the diagram is gone.
If you do a search on forward leakage current you will see some good articles on what happens with some electronic power switching devices .. one thing to remember is that these forward leaking voltages and current are additive - I had a truck stop fueling system that wouldn't shut down ... the state was about to shut the place down because the automatic leak detection system would not work unless the supply pump shut down for at least 15 min every 24 hours. Non of the pumps were calling for fuel but the relay that energized the supply pump was getting enough of a signal to pick up. Investigation showed the cumulative forward leaking voltage and current from all the pumps was enough to cause the supply pump system to stay on - I put ballast resistors from the output of the electronic power relay to the neutral to bleed the voltage and current off at every fueling station thereby causing the forward leaking voltage and current to be reduced to zero and allowing the supply pump to shut off when no dispenser was calling for fuel... it was quite the learning experience .. you have to be aware of this issue when dealing with electronic power switching devices. These issues also rear their heads when mixing electronic power switching and computer sensing circuits- you have to be carefull using low impedance systems to load electronic components - your testing can kill the components if you exceed their capabilities. Be Informed and be safe
@@jth1699 oh… my… god… that is a lot of text
I have mixed opinions on Dedicated Outdoor Air Systems (DOAS) for tempering outdoor air separate from the main space conditioning. It is required in some cases here in Washington, but it does add more components, ductwork, and system complexity that can confuse building owners and maintenance staff, leading to more issues down the road. Having a simple RTU, fan coil, split unit, etc. with a properly functioning economizer is still the simplest way to bring in normal amounts of outdoor air. DOAS has its place, and as a design engineer I have done them plenty of times, but they don't always make sense. Love the videos!
Hey Chris, you're awesome. Analytical thinking involves a methodical step-by-step approach to thinking, which allows us to break down such complicated technical problems into single parts. The way of visualizing your solutions make us understand them very quickly. Thank you for the great work. - Murat
Great video! Helps me as a BAS Programmer to relate to you HVAC guys better when you guys call in 😎
Excellent video and diagnosis!
Thanks for all your videos CHRIS are very helpful for me. your so knowledgeable.
Great troubleshooting!!! From a sparky!
That's TRICKY! Good Find.
Very interesting video, the rabbit holes were so plentiful. I could see how someone (probably me) could jump down a hole and spend so much time trying to figure out the problem. Thanks for offering a bird's eye view of the caution you take when drawing a conclusion and then not being sold on the conclusion being the answer until it's proven. As far as the mislabeling, I guess that's where I'd need to summons the patience and get the job done. As usual, you've brought another quality video. Thanks
PS - The economizer bringing in make up air that ranged around 96 degrees was on point. The minimum make up setting contributed heavily to the heat load in the room and the consideration is easily overlooked in the delta T assessment.
YORK Air handlers are very reliable. My company has dealt with them for years, and I can say from first-hand experience that they are great. They offer unbeatable competitive pricing and have amazing quality with an awesome Customer support team, as well as, technical team.
Voltage a little low, lol. Just as I was going to say trans set up wrong voltage you caught it.! Very common issue brother. Guys, this could be a problem with long runs of thermostat or control wires between ac and stat or energy management system. Good job, brother.
Good lesson on checking t stats.
Pro 8000 Honeywell? Love those stats.
I first started watching your videos when I first got into the industry and they were definitely helpful but a lot of times it was over my head. Now that I have a more practical understanding your videos are teaching me so much. Thanks for the help and keep up the great work!
Awesome Video!! You are 100% right about outside air needed to be conditioned beforehand. The commercial building that I work in has a ton of air handling units but we have 6 big outside air handler units that pump the air to the outher air handles and the ducts are labeled outside air. They have chilled water coils and steam coils for heat and eveything is controlled by a BMS system.
The ever elusive Phantom voltage. I keep a resistor on my van that I put between the common and the suspect wire that simulates a load if my voltage drops like it did in your video I call it as a bad relay contact on the t-stat and replace the stat.
What captured my mind in this video was that because of the low voltage between R and C because of the transformer is it possible the relay was "chattering" and experienced excessive wear.
I know on unloading compressors they have an H bridge to get DC power to hold the valve shut with single phase. Again because it opens and closes rapidly or "chatters" but that's also way more force required to hold those valves shut.
Thought provoking video thank you!
dirtbikenrcman what size resistor do you use?
I watch the whole video I love it I've been through the same situation and that's a headache when you are alone. You kept your cool in that 108 degree weather ! I would have been a bit cranky LOL
Good catch on the transformer!
Hey Chris, my bet is that thermostats were swapped by other technicians on previous service calls and the banquet room wasn't being used at the time so that's where the broken one was parked instead of the technician just taking the time to get a new tstat and base and doing the install. The labeling would be better placed on the wall, not on the tstats.
Watching these videos while attending school has been great since everything starts to make sense over the months, would love if you came to UEI in Riverside
I upgraded my thermostat to Honeywell, battery backup is so nice! I also like their programming for daily schedules, helps lower the utility bill without sacrificing comfort.
Honeywell also allows independent fan schedule so users can't switch to "ON" and forget to reset.
Here's why you saw 24V on Y1 and Y2 with the thermostat wires disconnected from the York board. The thermostat is very most likely using triacs instead of small relays to switch the 24V signals. A triac does not act as a switch or relay where it completely disconnects the output from the input. It only increases its resistance so as to prevent sufficient current from activating the load. I believe that a non energized triac has an impedence in the range of 40 Megaohms.
We can read the input voltage of the triac at its output when disconnected from its load with good multimeter because the impedence of a multimeter capable of reading very resistance is very high and as such makes the impedence of the triac negligable (to some extent) in the circuit with the multimeter.
The best way to test a triac is to connect it to a known good load (a 24VAC relay carried around) and see if it is triggered when the thermostat calls. In your case, you made a good call with the thermostat being that it was calling but not triggering the load.
You can find triacs on thermostat and also many BAS programmable PLC's. They operate silently and can also be switched at a high rate for baseboard or duct heater pulsing. I work with Alerton controls daily and 98% of the current controllers use triacs for their digital outputs.
Or you could just use low impedance input function on a multimeter to check if proper 24vac is being switched.
Great video as usual. But “very high humidity here at 50-55%” had to make be chuckle. Today in Florida the humidity is 83%...hold my beer.
Roger F how was Dorian
Dorian was like being in the Army...hurry up and wait. No wind, a little rain, maybe an inch for central and west Florida. However watching the news, one would think armageddon was upon us.
When you were explaining the voltage fluctuations during the summer I found thy very interesting. It almost makes me question the need for surge protection or low-voltage protection equipment.
brownouts are the legal term and way for companies to do that and when its hot everyone turns ac on so you get a heavy load and drops your voltage, as long as its not more then 10% your good most of the time and yes you need a surg protector in that case if they bolster the power and the units turn off you have a high inflow,
Another great video thanks for sharing your knowledge...
Good vid ! i Remember when i was first starting out the first thing i learned was allways Check your Transformer tap & secondary voltages. i used to find them on the wrong voltage All the time. Really common installer error in southern california i found. Ftngot - ALLWAYS The first thing u should do when u get to a package unit is check your transformer taps & voltage no Higher than 29 volts. at 30 volts Thermostats tend to Fry , thats what ive found anyway. i Like no higher than 27 volts & no lower than 23 volts. Good info on the Min outside air damper setpoint , if u have a unit struggling , You could Allways close that damper temporarily in the summer.
Re: Ftngot - Easy way to tell if its a bad thermostat in this case is to shut off unit, go down to thermostat , remove wires & wire nut together wires on R, G, Y1 & Y2. Go back up to roof turn on unit & if everything works. whala, junk thermostat.
By the way - I've Allways Loved that feature on Venstar thermostats or similar. Ftngot - i Allways Recommend You set up a Thermostat so, When Power From Roof unit is Dead Thermostat goes Blank. it's a Awesome Troubleshooting tool.
i Will ALLWAYS Do it that Way. Batteries in Thermostats is crap, ALLWAYS WIRE IN THE COMMON WIRE. Makes Your Life a Whole lot easier ! Wayyy Less Thermostat Problems with a Common wire hooked up i have found.
Excellent situation what you come across and could scratch your head 👏 👍
good job thank you MR.Stephen.
Apparently, the mislabeled and malfunctioning thermostat was acting like camouflage, effectively thwarting the Predator.
11:54 oh fuck, here we go again!!! Chris, what have I told you that the "U" in "RTU" stands for?????? LOL!!!
Excelent skills, keep with a good work and videos
more more! these videos are awesome! and your advice is so helpful! learning so much from you sir!
Good call on changing over from 240 to 208 volts on the transformer. That was an issue I ran into a few years ago where there was 208 going into the units and they were plugged in for 240. More than half of the transformers fried on 14 newly installed package units
Great Video Chris! You are right about the OSA with the economizers I have been complaining for years about that situation.
Awesome vid I been in the field for less than a year and low voltage is a real struggle.
Process of elimination nice work
Though I very seldom have worked with that many stats clustered I can see your frustration and returning to correct it. Not OCD but just plain common sense!
Good tip on the 208/230 tap selection on the 24V transformer, I've seen most units never have an issue with it but change it over anyways especially since York tech support had informed me once that sometimes their boards can act up when they get on the lower end of control voltage.
a,b,c,d settings, got to love them, man i miss service calls think i should move to ca looks like you guys have fun
@ 6:05 good idea to use meter for current draw through jumper or total current from transformer secondary. before just stuffing in a new t.stat, yeah I've cooked a few new ones myself, within hours to days =p
Great info. Appreciate it.
Honeywell will forever dominate the thermostat market. Good diagnosing
You make this look easy
not to sound like a ass but that would be a super easy call for most commercial techs, you will get to the point that its second nature. people will say i have this unit or the color of the unit and you will here the problem and know what it is, and leaks that occur in the same place thanks to bad design am looking at you trane
It may be an easy call but everyone has a method and way they go about things. And I watch his videos and he goes at each issue with his same style and always gets to the point and I respect that. Any trade you learn you start off with no style then you develop it thru the yrs. also, simple shit stuns the most vets all the time
Excellent video and job 👍👍👍
Nice work sir
Hey Chris! Great video as always. Man ! Coachella. We’re cool 😎 down here in San Diego. Only 90•. Have a great Sunday! God bless.
Great vid thanks. I get 9 flashes while trying to run AC. 9 flashes indicates ignition lockout.
Wish we had someone like you in Phx haven't found one yet. I seem to end up with Techs that guess at solutions more than discovering what is wrong. I manage 5 units about 25 tons worth.
well if i move there you got me, i manage at my building 12 units 200 to 250 tons each and 8 16 ton units, and hundreds of vav boxes and i do all the programs for the crappy andover continuum system.
have been in the trade for 22 yrs now did a lot of the gov buildings and cooling towers and a bunch of others,
i hate dealing with "tech"s mechanics also known as parts changers, these younger guys just dont look half the time. they guess what it is on the way to the call
Great video bro
Thanks bud
Lo-Z function on your DMM would / could have helped. I've run into many high impedance circuits that show unloaded supply voltage on a DMM. As soon as you apply a connected load, the voltage disappears. In the early days we used a wiggy tester (before Lo-Z was an option on DMM's), but if you don't have a DMM with the Lo-Z functions you can use any known good load appropriate for the voltage being tested.
Excellent video!
Thanks, I will be going live on RUclips this evening 9/9/19 @ 5:PM (west coast time) to discuss my most recent uploads, answer questions from RUclips comments, the Live chat, and from emails if you can come check it out here is the link >>>> ruclips.net/video/6YDWpK7UEiU/видео.html
Great video thanks
Great content techs need to have alot of infro
Just a heads up . Here on Long Island New York we have the same issues with transformers being tapped to 240. When in actuality it was 208 . Great info as usual
I sold industrial HVAC and my boss has sold a used direct-fired air makeup that had work for a year and when they tried to start it up the unit would not run. When I went to the roof and open a panel and tried to start the unit fired right up. The air was dumped into a square duct the four dampers on the discharge, well a the dampers were almost completely shut so the sensor said there was not enough air flow to start. So I talked to the maintenance guy and had him remove a damper the shot down a hallway, never had a service call on that unit again.
Good catch
Great job again like always
I know this video is two years old. Good job on thermostat tap. I always make sure the thermostat is set right.
Just had a similar issue at a Goodwill store. A second company had come out and installed 5 new wireless Emerson thermostats and wireless sensors. Not only had they labeled everything incorrectly but half of the sensors didn't even have batteries. This lead to three t-stats not being able to send a signal out to the units. What a mess!
2:50 start up tech fail.
Great video, do you carry alligator jumpers ever?
Last friday I had 11 York's to run PM's on at an AMF bowling center in Rochester NY.
The jumpers come In Handy testing rtu functions.
Great vid!!!
Great video!!!
Doing a great job . Looks like the Nat. gas code is not very strict in California no dirt pockets ect. In Canada it is very strict ,Everything must be to the latest code .
It’s crazy how many package units I come across that are 208-3 phase voltage and the transformer is tapped for 240 volts. I change them everytime I see it, because just like in your video, there is a big difference in the low voltage output without a load on the unit. It will go from something around 23-24 volts without a load to 26-28 volts which is what you want.
Thanks for the videos you do. There are great. Where I can find more information about RTUs am new at this trade and you are inspirational thanks
Love the channel
Very nice work! Hard to believe someone would go to all that trouble to lable the thermostats, and then do it wrong lol. Have heard there are CO2 sensors to control the economizer for fresh air. That way it only takes in outside air when it's necessary, not all of the time.
Yes we do use c02 sensors but we will still usually set the minimum outside air at a certain setpoint than the c02 sensor will adjust the damper open as more people occupy the building. I will discuss this on my stream tonight, I will be going live on RUclips this evening 9/9/19 @ 5:PM (west coast time) to discuss my most recent uploads, answer questions from RUclips comments, the Live chat, and from emails if you can come check it out here is the link >>>> ruclips.net/video/6YDWpK7UEiU/видео.html
Not really familiar with the economizer set up do to being in Florida, too humid for many applications but, have worked on some carrier and Trane over the years. Question is, don't the economizer use Enthalpy and temp to adjust the level of outside air allowed into the Return Air? And if yes, would the fresh air shut down in the case of 100 degree plus outdoor ambient or are they set up to allow a certain percent of fresh air regardless of Outdoor temp? I know that's a lot😄
Thank you!
coolezum
You have several ways of controlling an economizer including outdoor temp, enthalpy and dual enthalpy. No matter the type of control you will have a minimum position, usually in the 10-20% range. So whenever the blower is running you are pulling in outside air to maintain fresh air requirements and building pressure. When the criteria is met for free cooling, your economizer will open to 100% upon a call for cooling and again, their is several methods to control that. Ie.say you have a temp setpoint of 55degrees for free cooling and it is below 55deg. Outside, instead of energizing the compressor it will open the economizer. Same situation with enthalpy. If outdoor air is below the enthalpy set point, it will utilize outdoor air for cooling instead of mechanical cooling. In dual enthalpy, the unit will monitor building and outdoor enthalpy and utilize whichever is suitable. You can also monitor return, outdoor and supply conditions and use a combination of economizer and mechanical cooling to maintain a specific supply temp. You can also have demanded ventilation utilizing IAQ requirements to call for economizer operation. As with anything in this trade, read the damn manual! I can’t say that enough. It’s a simple thing we all to often don’t do then can’t figure out why we have issues properly setting up new equipment or diagnosing equipment we encounter.
Kevin King thanks man, good explanation. I knew most of the details but, just was not sure if there was a way to shut down the economizer in an event such as happened on this problem, where as no cooling ,yet was dumping OSA into the building. No safety where as a sensor could close the economizer off completely in this situation. Cool man, peace
@@kevcooh9 and the econ is used as stage 1 cooling on some units like carrier then stage 2 is the compressor and thats with lower outdoor air temp and if the unit cant pull down it will say the hell with the econ and bring the 2nd compressor on so in lower temps in a club or bar a place that has a high heat load you will see the compressor and econ on then 2 comps and no econ.
keep thinking
Yes sir, you are correct
208V vs 240V is generally 3-phase vs single phase service even with a single phase unit. This is bc 208V is phase to phase voltage and 120 phase to ground vs 240V split phase which is 240V line to line and 120V line to ground.
Typical three phase is delta wye, which provides the 208 and 120. Atypical is delta high leg or wild leg... gets you 240, 120, and 208 volts. Then there's delta only, no neutral, usually for industrial motors that isn't seen in this stuff.
Great video! I changed my name to fit in with all you other refrigeration gurus. 😁😁
Well I guess the change diddnt show up yet lol
Hi Chris were can us Aussies get your flexible water hoses they are so cool we cant get them here in Australia.
thermostat not passing enough current, bad relays or connection. or corroded splices/connections somewhere along the thermostat wiring. fire system relay?
Good one
When I saw that fire alarm box inside the unit i kept wondering if the alarm switch had tripped and turned the unit off.
Where I live in Australia where all on 240 volts we also have 415 3 phased and 415 2 phase split phase
if I had a $1 for every unit I found the trans tapped on the wrong tap I would be rich. Also digital meters are great, but they put no load on the circuit and they will show transient voltage when there is really nothing there.Sometimes using a "wiggy" or an analog meter is better.Mismarked is worse than no markings sometimes
hahahaha a wiggy still have a old wiggy use it to show the newer guys what i started in school with and remember 10 wraps of t-stat wire to read the mili volts for the heat anticipator load
Fantastic video even tho I haven’t watched it yet lol but I know you brother and your skills !!!!
Good one. U troubleshoot just like I do.
Makes you wonder if that unit is the right solution if it has to pull triple duty cooling the room, cooling the fresh air, and dehumidifying all of it. Perhaps there is a more efficient alternative?
208Y/120V 3phase is fairly common all over the place for light commercial, strip malls, until you get into larger industrial complex which are 480Y/277V as primary voltages.
around here they often have their own large pad transformer/s with 14.4KV or higher, being stepped down to 208Y/120 or 480Y/277V and another step-down inside for lighting and other smaller loads. it really depends on the area and existing grid, it can vary from section of town to section of town depending on age of the grid and upgrades. I wont delve into "delta" supply voltages.
anyway often you'll see single phase 480Y primary to 240/120v transformers just for common use outlets and devices.
Yeah I've come across some funky delta supplies....... the most memorable was a corner grounded delta....... the first time I came across that I was on the phone with an electrician buddy right away.....
Yeah- any time you see a breaker box with every third breaker missing BEWARE - that missing breaker will be the wild leg... I have seen some electricians be very embarrassed by grounded deltas.
That was great. I pull the batteries on those stats.
Super
when calling for cooling, only y2 comes on. why install a delay on make timer between contactor 2 to contactor 1 to kick on the compressor 1?
Is that a Simpson 260 analog multimeter on the corner shelf behind you? If so, did you ever use it, or is just a piece in your collection? Another good video, by the way.
No i never used it, it was my dads and I just grabbed it for my office
One of the worst mislabeled items would be the fire suppression system in the restaurant. We would take the charge bottle out of the Ansul cabinet and then cut the cable at the fry station. What a mess it made, there was powder, err sorry Ansul, chemical all over the kitchen.
Very helpful
Hot dog hot dog !!! Great job
4:16 was trying to pan camera down almost after coming back from 7:20
240V/208V is depending on the supply, if the transformer is a 2ph 180° 120V the voltage between the two phases is 240V; if its a 3ph 120° 120V you messure 208V between two phases; as the us is mostly 2ph 180° for residential areas its more common to find 240V in some areas
Any idea why inland California has low voltage issues?
They shut down plants left and right because of "environmental" reasons. Then they purchase power from out of state. Guess what, the other states use more power in summer because it's hot as hell. There's increased loads from 60 million people at once, something has to give. Voltage sags. Not a big deal, most the time, most equipment are built to handle the variance. Sags too hard and we'll, you get Brown outs that does affect equipment. Then you get power stations tripping and blackouts.
California wants their cake and to eat it too. Simply doesn't work that way.
We pay peak pricing out here in the west because when there is peak usage, the utility usually has generators on standby they can fire up, basically a makeup unit. I think gas burning. Either way it costs a lot more to get that going but that's what usually provides the power boost during the heaviest of loads. California... well, if it's cloudy or not windy all those "green sources" don't output shit and you get California power problems.
A couple nuke plants would fix all that but most the idiot voters won't do a thing. Inland empire is newer build and lesser money than the big cities with their rich folk so they'll always be the red headed step child and take the brunt of issues.
@@etherealrose2139 California has 3 main power companies: PG&E for Northern and Central CA; SoCal Edison for most of southern part of the state: and SDG&E for San Diego area. SoCal also gets power in summer from West Coast Intertie from Grand Coulee Dam in WA. In winter excess power is sent north for electric heat in WA and OR. At least that's the way it used to work.
👌
do you work illinois?
In Germany the mains voltage is 230V/400V